石斛篓象的生物学特性

Bionomics of Nassophasis sp.

石斛篓象Nassophasis sp.为石斛的重要害虫之一,在云南普洱地区1年发生2～3代,世代重叠。3～4月和9～10月为幼虫发生高峰期,6月、12月为成虫发生高峰期。石斛篓象以幼虫蛀茎为害为主,成虫亦为害石斛茎、叶,石斛篓象对球花石斛为害最为严重。昼间取食的成虫数量关系为午后(13:00～14:00)>傍晚(17:30～18:30)>清晨(8:30～9:30);各时段成虫数量与平均温度有一定正相关;成虫在清晨较喜食叶,在午后、傍晚则较喜食茎。

Nassophasis sp. is a serious pest on Dendrobium Sw. in recent years. It had two or three generations one year with overlapped generations in Pu＇er of Yunnan province. Both the adults and the larvae had two peaks of occurrence. The peaks for larvae took place in March to April and September to October,and in June and December for adults. The host plants were damaged mainly by its larvae. The larvae were stem borers,and adults damaged both stems and leaves. Dendrobium thyrsiflorum was the most severely damaged. The number of the feeding adults in the afternoon （13：00～14：30）was obviously higher than those in the morning（8：30～ 9：30） and in the dusk（17：30～18：30）. It was positively related to the average temperature. The adults preferred the leaves to the stems in the morning,and preferred the stems to the leaves in the afternoon and dusk.